Background: Standards set by the National Neonatal Audit Programme (NNAP) emphasise the importance of preventing hypothermia during stabilisation and initial transport of preterm newborns (1). Placing the infant in a plastic bag prevents hypothermia (2) and is standard practice in the UK3. There have been mixed results when gel warming mattresses (Transwarmers) have been used in combination with plastic bags (3,4). We hypothesised that hypothermia could be prevented using Transwarmers without the use of plastic bags.

Methods: This retrospective observational study capitalised on a pre-existing difference between policies at Unit 1 (Transwarmers without plastic bags, Resuscitaire transport from labour ward to the neonatal unit) and Unit 2 (plastic bags, incubator transport). Both are Level 3 neonatal intensive care units (NICUs) in close proximity to delivery areas. We compared rates of hypothermia (<36.5ºC) on arrival to the NICU in all infants born in the relevant hospitals at less than 30 weeks completed gestation in each unit over a period of seven years (2010- 2016, 974 total deliveries). Routinely collected data were gathered by interrogating BadgerNet data sets.

Results: Rates of hypothermia were lower than the national average in both units and improved over time as compliance with policies improved. The overall rate of hypothermia did not differ (17% vs 18%, Fisher’s Exact Test, p=0.67).

Conclusion: Using a Transwarmer alone is not inferior to using plastic bags in the stabilisation and initial transport of premature newborn infants. Either modality can outperform the national average. Further studies could analyse efficacy of either in the context of delayed cord clamping, proximity to the neonatal unit, and mode of transport.